> On Feb 25, 2015, at 18:08, Kevin Oberman <rkoberman_at_gmail.com> wrote: > >> On Wed, Feb 25, 2015 at 2:30 PM, Garrett Cooper <yaneurabeya_at_gmail.com> wrote: >> On Feb 25, 2015, at 14:19, Miguel Clara <miguelmclara_at_gmail.com> wrote: >> >> ... >> >> > I noticed this too, but in that case why doesn't it affect all users? (or all the ones using dnscrypt+local_unbound) maybe something changed in "NETWORKING" recently? >> > >> > Hum: >> > https://svnweb.freebsd.org/base/head/etc/rc.d/NETWORKING?r1=275299&r2=278704 >> > >> > Interesting, as I am using the most recent version which does not REQUIRE local_unbound >> > >> > I'm even more confused now :| >> > >> > >> > So it has to come after SERVERS but before local_unbound. But NETWORKING depends on local_unbound they are both dependent on NEWORKING which has to be after SERVERS. Can you say fubar! Clearly broken. And this means that removing SERVERS will re-shuffle the order more appropriately. >> > >> > It seems that the behavior of rcorder is not as documented as well as being undefined when circular dependencies occur. The man page says that rcorder aborts when it encounters a circular dependency, but that is not the case. It probably is best that it not die, but that leaves things in an unknown and inconsistant state, which is also a very bad idea. I guess when a circular dependency is encountered, a dichotomy occurs. >> >> Now you know why Ifm so curious about all of this stuff. >> >> When I was working on ^/projects/building-blocks, I was able to move most of these pieces around by changing REQUIRE: to BEFORE:, but I noticed that it changes the rcorder a bit, so I havenft been super gung ho in implementing my change. >> >> I think there are a couple bugs present on 9-STABLE/10-STABLE/11-CURRENT: >> >> - Things go awry if named is removed/not installed. >> - Things go awry if local_unbound is removed (which would have been the case if the rc.d script was removed from your system, which existed before my changes). >> - Other rc.d scripts not being present might break assumptions. >> >> I need to create dummy providers for certain logical stages (DNS is one of them) to solve part of this problem and provide third parties with a mechanism that can be depended on (I wish applications were written in a more robust manner to fail gracefully and retry instead of failing flat on their face, but as Ifve seen at several jobs, getting developers to fail, then retry is hard :(c). >> >> Another short-term hack: >> >> Install dummy/no-op providers so the ordering is preserved, then remove the hacks after all of the bugs have been shaken out. >> >> Thanks! > > Garret, > > Also undocumented (except in rcorder.c) is that the lack of a provider is not an error. This effectively makes a list of providers into an OR. So, for name service the normal list is "named local_unbound unbound" and any will work for ordering and having none is a no-op, so if you don't run any nameserver (or kerberos or whatever provider), it is not an issue. As long as rcorder finds a provider, it will be used to set the order, but the lack of any or all providers just means that the specified provider is ignored and if a REQUIRES or BEFORE lists no existing providers, the statement is simply ignored. > > The real problem is that there is no defined rule for behavior in the event of a circular dependency and any change to any decision point in the ordering process may change the way the ordering flips. That is why these things are such a royal pain to debug. A change in any rc.d script may cause the ordering of seemingly unrelated scripts to change, perhaps drastically, and the error messages, while not misleading, is only a starting point in tracking this down. This means there may be time bombs that break working ports without their being touched or even re-installed. And the triggering change my, itself be correct. Or etc/rc.d/named... PROVIDES: DNS I'm going to post a fix up for this on arch_at_/rc_at_ because it needs to be solved in a saner way -- especially for systems that are pedantic about rcorder, like our version at $work.Received on Thu Feb 26 2015 - 01:52:41 UTC
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